Objective: To investigate the transcriptional activity of P53 in gastric cancer.
Methods: The activity of p53 in gastric cancer was investigated by dual-luciferase reporter assay. The coding sequence of the p53 was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. The expression of P21WAF1/Cip1, Gadd45alpha and Mdm2 was detected by immunohistochemistry in 76 samples of gastric carcinoma, and their adjacent tissues were analyzed as control.
Results: The p53 activity was higher in human normal cell lines than that of gastric cancer. Furthermore, the transcriptional activity of P53 was lowest in MKN28 cells in which p53 was mutated. The expression level of P21WAF1/Cip1, Gadd45alpha and Mdm2 in the adjacent tissues was higher than that of cancer tissues (P<0.05), and there was a tendency of decline in the positive ratio with the poor differentiation of the carcinoma (P<0.05). In addition, a strong linear correlation was observed between P21WAF1/Cip1, Gadd45alpha and Mdm2 (P<0.05).
Conclusion: Changes of P53 transcriptional activity play an important role in the development of gastric cancer. p53 mutation could affect its transcriptional activity. P21WAF1/Cip1, Gadd45alpha and Mdm2 are a group of effecters that could reflect P53 transcriptional activity when detected together in cancer tissues.